package com.example.common.utils.excel;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * 读写excel文件类
 *
 * @author JokerJodas
 */
public class ExcelUtil {

    private static Logger logger = LoggerFactory.getLogger(ExcelUtil.class);

    private final static String XLS = "xls";

    private final static String XLSX = "xlsx";

    /**
     * 读入excel文件，解析后返回
     * @param file
     * @throws IOException
     */
    public static List<String[]> readExcel(MultipartFile file) throws IOException {
        //检查文件
        checkFile(file);
        //获得Workbook工作薄对象
        Workbook workbook = getWorkBook(file);
        //创建返回对象，把每行中的值作为一个数组，所有行作为一个集合返回
        List<String[]> list = new ArrayList<String[]>();
        readFromWorkbook(workbook,list);
        return list;
    }
    /**
     * 读excel文件，解析后返回List数据
     * @param workbook list
     * @throws IOException
     */
    public static List<String[]> readFromWorkbook(Workbook workbook, List<String[]> list) throws IOException {
        if (workbook != null) {
            // 获取当前Excel中sheet的数量
            int sheetNums = workbook.getNumberOfSheets();

            for (int sheetNum = 0; sheetNum < sheetNums; sheetNum++) {
                //获得当前sheet工作表
                Sheet sheet = workbook.getSheetAt(sheetNum);
                if (sheet == null) {
                    continue;
                }
                //获得当前sheet的开始行
                int firstRowNum = sheet.getFirstRowNum();
                //获得当前sheet的结束行
                int lastRowNum = sheet.getLastRowNum();
                //循环所有行
                for (int rowNum = firstRowNum ; rowNum <= lastRowNum; rowNum++) {
                    //获得当前行
                    Row row = sheet.getRow(rowNum);
                    if (row == null) {
                        continue;
                    }
                    //获得当前行的开始列
                    int firstCellNum = row.getFirstCellNum();
                    //获得当前行的列数
                    int lastCellNum = row.getPhysicalNumberOfCells();
                    String[] cells = new String[row.getPhysicalNumberOfCells()];
                    //循环当前行
                    for (int cellNum = firstCellNum; cellNum < lastCellNum; cellNum++) {
                        Cell cell = row.getCell(cellNum);
                        cells[cellNum] = getCellValue(cell);
                    }
                    list.add(cells);
                }
            }
            workbook.close();
        }
        return list;
    }

    /**
     * 读取excel
     * @param filePath
     * @return
     */
    public static Workbook readExcel(String filePath){
        Workbook wb = null;
        if(filePath==null){
            return null;
        }
        String extString = filePath.substring(filePath.lastIndexOf("."));
        InputStream is = null;
        try {
            is = new FileInputStream(filePath);
            if(".xls".equals(extString)){
                return wb = new HSSFWorkbook(is);
            }else if(".xlsx".equals(extString)){
                return wb = new XSSFWorkbook(is);
            }else{
                return wb = null;
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return wb;
    }
    //转存excel
    public static void saveExcel(String filePath,byte[] bytes){
        Workbook wb = null;
        String extString = filePath.substring(filePath.lastIndexOf("."));
        InputStream is = null;
        try {
            is = new ByteArrayInputStream(bytes);
            if(".xls".equals(extString)){
                 wb = new HSSFWorkbook(is);
            }else if(".xlsx".equals(extString)){
                 wb = new XSSFWorkbook(is);
            }else{
                 wb = null;
            }
            FileOutputStream os = new FileOutputStream(filePath);
            wb.write(os);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 检测文件存在
     * @param file
     * @throws IOException
     */
    public static void checkFile(MultipartFile file) throws IOException {
        //判断文件是否存在
        if (null == file) {
            logger.error("文件不存在！");
            throw new FileNotFoundException("文件不存在！");
        }
        //获得文件名
        String fileName = file.getOriginalFilename().equals("") ? file.getName() : file.getOriginalFilename();
        //判断文件是否是excel文件
        if (!fileName.endsWith(XLS) && !fileName.endsWith(XLSX)) {
            logger.error(fileName + "不是excel文件");
            throw new IOException(fileName + "不是excel文件");
        }
    }

    /**
     * 根据文件结尾获取不同WorkBook实现
     * @param file
     * @return
     */
    public static Workbook getWorkBook(MultipartFile file) {
        //获得文件名
        String fileName = file.getOriginalFilename();
        //创建Workbook工作薄对象，表示整个excel
        Workbook workbook = null;
        try {
            //获取excel文件的io流
            InputStream is = file.getInputStream();
            //根据文件后缀名不同(xls和xlsx)获得不同的Workbook实现类对象
            if (fileName.endsWith(XLS)) {
                // xls
                workbook = new HSSFWorkbook(is);
            } else if (fileName.endsWith(XLSX)) {
                // xlsx
                workbook = new XSSFWorkbook(is);
            }
        } catch (IOException e) {
            logger.info(e.getMessage());
        }
        return workbook;
    }

    public static String getCellValue(Cell cell) {
        String cellValue = "";
        if (cell == null) {
            return cellValue;
        }
        // 把数字当成String来读，避免出现1读成1.0的情况
        if (cell.getCellTypeEnum() == CellType.NUMERIC) {
            cell.setCellType(CellType.STRING);
        }
        //判断数据的类型
        switch (cell.getCellTypeEnum()) {
            case NUMERIC:
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case STRING:
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case FORMULA:
                cellValue = String.valueOf(cell.getCellFormula());
                break;
            case BLANK:
                cellValue = "";
                break;
            case BOOLEAN:
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case ERROR:
                cellValue = "非法字符";
                break;
            default:
                cellValue = "未知类型";
                break;
        }
        return cellValue;
    }
}